Field
This invention relates generally to the field of diffractive lenslet optics for spectral imaging and more particularly to an image array employing order filters associated with pixels or pixel groups in an image array for enhanced detection of higher order wavelengths and a controller for gas detection based on relative intensity of radiation passed by the order filters.
Description of the Related Art
Spectral imaging may be accomplished using circular blazed grating diffractive lenslet arrays to discriminate various wavelengths. The preparation of diffractive lenslets for radiation, such as radiation in the visible and infrared bands, requires precision grinding to provide appropriate blazing. Additional precision in discrimination of properties of the incoming radiation to a detector for depth measurement in a substance or other characteristics is also desired. Spectral imaging may be employed for remote sensing and gas detection.
It is desirable to provide a spectral imaging system which reduces the precision required for blazing of lenslets or conversely enhances detection at a given precision and provides discrimination capability for gas detection.